certify in WordNet English dictionary

1. provide evidence for; stand as proof of; show by one's behavior, attitude, or external attributes
   "His high fever attested to his illness"; "The buildings in Rome manifest a high level of architectural sophistication"; "This decision demonstrates his sense of fairness"
   attest  certify  manifest  demonstrate  evidence 
   
2. declare legally insane
   certify 
   
3. guarantee payment on; of checks
   certify 
   
4. guarantee as meeting a certain standard
   "certified grade AAA meat"
   certify  endorse  indorse 
   
5. authorize officially
   "I am licensed to practice law in this state"
   license  licence  certify